Traditionally, computer users have stored personal digital information at their personal computing devices. For example, after editing a word processing or spreadsheet document using a personal computer, the user saves the document to the computer's hard drive. In recent years, however, the cost of personal computing devices has lowered to the point where a user can own multiple personal computing devices and store personal digital information at each of them. For example, a user may own a laptop computer that stores the user's work documents and a mobile phone that stores the user's digital photos. In some cases, a user may store personal digital information at a personal computer the user does not own but nonetheless uses regularly or periodically, such as a school or work computer.
Today, many users “host” their personal digital information with online content management services. Such services typically allow users to upload their personal digital information for storage at service-operated server computers accessible on the Internet or other communications network. One well-known online content management service is the DROPBOX file hosting service provided by Dropbox, Inc. of San Francisco, Calif. Hosting personal digital information with online content management services provides a number of benefits to users. For example, such services typically allow users to back up, share, synchronize, access and store their hosted digital information.
Although the wide-availability of the broadband Internet connectivity has made it possible for users to use their personal computing device to remotely access personal digital information hosted with online content management services, there are still situations in which users would prefer to store copies of their hosted personal digital information at their personal computing devices for the purpose of facilitating “local” access to the information. For example, a user may wish to store a word processing document on a storage device (e.g., a hard disk) of a laptop computer to have access to the document when using the laptop computer on an airplane or in another location where Internet connectivity is unavailable or difficult or inconvenient to obtain.
There are various different approaches that online content management services could adopt for storing hosted personal digital information at user computing devices for the purpose of facilitating local access to the information. For example, in one possible approach, a copy of all or most of a user's hosted personal digital information is stored at the user's computing device. However, this approach may not be practical if the user's computing device has limited storage capacity. For example, the user may host hundreds of gigabytes (GB) of personal digital information with an online content management service and regularly use a mobile phone that has only thirty-two gigabytes (32 GB) of hard disk storage capacity. In this case, even with data compression, it may not be possible to store a copy of all or most of the user's hosted personal digital information at the user's mobile phone.
In another possible approach, only a copy of the most recently accessed hosted information is cached at a user's computing device. According to this approach, when a user accesses hosted digital information from the user's computing device, the information is downloaded from the online content management service to the user's computing device and stored there (e.g., on a hard drive of the user's computing device) for some period of time. Less recently accessed information may be deleted from the user's computing device to make room at the user's computing device for more recently accessed information. However, this approach can be ineffective or inconvenient for the user if the user attempts to access hosted information that is not already cached at the user's computing device. For example, upon attempting to access a hosted document, the user may be required to wait for the document to be downloaded from the online content management service over the Internet to the user's computing device before the user can view or edit the document, which the user may find tedious and time consuming, especially if the user's computing device is connected to the Internet via a relatively low bandwidth or high latency data network, such as, for example, a cellular telephone network.
Given the increasing digitization of the world's information, user demand for hosting personal digital information with online content management services can only be expected to increase. This trend is coupled with a need of users to be able to more easily access hosted digital information locally at the users' personal computing devices. The present invention fulfills this and other needs.